I have a 15 AMP breaker that will not stay on. Shut off lights, went to bed as usual and in the morning the lights would not come on. I inspected the breaker panel and found that circuit was tripped. When I tried to flip it back on, it lasted less than a second with a sort of "bzzzz pop" sound. Same results every time I try to flip it back on - seemed like a short to me.

This breaker covers the overhead lighting (13 recessed flood lights) for 2 rooms and vanity lighting (4 LED bulbs) and 2 outlets (1 is GFCI) in a bathroom. There is a light switch in the bathroom, a light switch in one room and a dual switch in the other (one for each room). I figured I'd start ruling out components one by one.

In order to troubleshoot, I first removed all the bulbs just in case there was a bad ballast causing an issue - no change. I then removed the leads on all the outlets and light switches and tried again - no change. I then swapped out the breaker in the main panel - no change. I crawled into the attic and didn't see any damage (though a lot of the wiring is not easy to get to, I saw no evidence of animals chewing through anything). Is there anything I'm missing that I could look at?

  • Did anyone hang any pictures or do any repair work? – JACK Sep 14 '19 at 20:44
  • Nope. The only thing that happened is that I shut the lights off and went to bed. In the morning they didn't come on again. No work or maintenance or anything else between those two points in time. – MaQleod Sep 14 '19 at 21:01
  • A longshot but check the switch – JACK Sep 14 '19 at 21:04
  • I disconnected all the switches and outlets on the circuit and tried it, no change. – MaQleod Sep 14 '19 at 21:04
  • All you can do now is isolate each load (room) hot and common. Test the first section from the breaker to the begining of the first load. If the breaker holds, that section is good. connect the second section of load and test... and so on until you add a section that trips the breaker... – JACK Sep 14 '19 at 21:28

In most cases of getting a "bzzz pop" on a circuit breaker there is a 98% chance you have a direct short to ground and if this happens once you shouldn't keep trying. The only thing it does is cause further damage to your electrical system.

The first thing I would do is to turn very switch to the off position and unplug every piece of equipment from the system. I would remove the panel cover and using an ohm meter or continuity tester to see if I got a "ring" between the load side of the breaker and the neutral/ground buss which indicates a short. Or you could just reset the breaker if you don't have any meters but remember you are damaging your circuit and the breaker.

So if you do not get a ring or the breaker stays on, then you know it is not the receptacles or the switches. Now you know the short is after one of the switches and probably in one of your light fixtures. You can then go around and turn on each switch on until you get a ring. This will locate which lighting branch is shorting out and you have at least isolated the problem to a smaller area of the circuit.

If you do get a ring or the breaker trips off, you know the short is either before the switches or at one of the receptacles. Experience would tell me to check the receptacles first.

Shorts are easy to find since they are and arc flash and create a lot of heat. so there will be the smell of something burnt, melted wire, blackened residue and melted insulation.

Removing lamps form light fixture really doesn't help especially in fluorescent fixtures with ballasts and LED's with drivers. These ballasts and drivers use energy regardless if the lamps are plug in or not.

Isolating and locating where the problem is allows you to make better informed decisions on if its a simple fix you can handle or you need professional help.

FYI - since you have already turned the breaker on let it trip multiple times. It may be a good idea to change out the breaker. It is probably not operating within allowable tolerances (laymen terms the contacts are burnt and the bi-metal trip material is damaged).

Good luck

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  • I'll give this a shot. My main problem is that one of the rooms has two switches, so I am not sure at this point when they are in the "off" position or "on" position as those positions are relative in this configuration. – MaQleod Sep 15 '19 at 18:49
  • And just to be clear, when you say remove every piece of equipment from the system, do you mean everything in the house? or just everything on that circuit? – MaQleod Sep 15 '19 at 18:49
  • @MaQleod - The switches you are referring to are 3-ways which work in combination so if you turn off the circuit, you can then open one switch and remove the common conductor (one post will be a different color or identified) and then put a wirenut on it you will disconnect the circuit from that lighting branch. Also, just to be clear, I am talking about just the one circuit. – Retired Master Electrician Sep 15 '19 at 18:59
  • I pulled out the switches that were in the 3-way config, tested continuity to either side and left them in the position when continuity was broken between the sides - so they should both be in the "off" position. With that, I got a beep from the meter when testing continuity between the breaker and neutral/ground bar. Quick question - is it expected that other circuits that are on/in-use would also show continuity between load and the bar? – MaQleod Sep 15 '19 at 21:57
  • Uppdate: bathroom outlets and light switch do not show continuity to ground. The light switches in the two other rooms do. I found another GFCI outlet that I had long forgotten about as it is in a really odd place, but is on the same circuit and the top receptacle does not show continuity to ground, but the bottom one does. I removed this outlet entirely and there is no change in status at the breaker - still getting continuity there - so I'm guessing it is something on the wire between the outlet and the breaker box? – MaQleod Sep 15 '19 at 22:58

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